in a young double slit experiment, two parallel slits with a slit separation of $0\mathrm{.}100$ mm are illuminated by light wave length of $589$ nmm$,$ and the interference pattern is observed on a screen located $4\mathrm{.}00$m from the slits. a$)$ what is the difference in path lengths from each of the slits to the location of the center of a third order bright fringe on the screen b$)$ what is the difference in path lengths from the two slits to the location of the center of the third dark fringe away from the center of the pattern